1. Field of the Invention
The present invention relates generally to scored reverse buckling rupture disk assemblies, and more particularly, to an improved scored reverse buckling rupture disk assembly which includes a supporting member for preventing a blow-out portion of the rupture disk from tearing away therefrom.
2. Description of the Prior Art
Many pressure relief devices of the rupture disk type have been developed and used heretofore. Generally, such devices include a rupture disk supported between a pair of support members or flanges which are in turn connected to a relief connection in a vessel or system containing fluid pressure. When the fluid pressure within the vessel or system exceeds the design rupture pressure of the disk, rupture occurs causing pressurized fluid to be relieved from the vessel or system.
Rupture disks of the reverse buckling type have heretofore been developed and used successfully. Reverse buckling rupture disks include a domed portion and the fluid pressure from the vessel or system being protected is exerted on the convex side of the disk. Upon failure, the domed portion of the disk reverses and then ruptures. Originally, all reverse buckling rupture disk assemblies included knife blades positioned adjacent the rupture disks thereof on the outlet sides of the disks. Upon reversal, the disks impaled on the knife blades causing them to open in a predetermined manner. More recently, reverse buckling rupture disks have included scores on a surface thereof which create lines of weakness therein so that upon reversal, the disk tears along the lines of weakness. U.S. Pat. No. 3,484,817 issued Dec. 16, 1969 describes the construction and operation of scored reverse buckling rupture disks. A method of manufacturing scored reverse buckling rupture disks is described in U.S. Pat. No. 3,921,556 issued Nov. 25, 1975.
While scored reverse buckling rupture disks have been used successfully and have obviated the need for knife blades in a number of applications, fragmentation of scored reverse buckling rupture disks has heretofore been a problem in applications involving high pressures. That is, upon the reversal and rupture of a scored reverse buckling rupture disk along the lines of weakness formed by the scores in high pressure applications, fragmentation often occurs due to the high speed at which the disk reverses and the explosive nature of the ensuing rupture. Also, if some of the heretofore used reverse buckling rupture disks are damaged in installation or handling, they can reverse and not open until fluid pressure higher than the design rupture pressure is exerted thereon causing an unsafe condition to exist.
In order to lessen the chances of fragmentation upon the rupture of scored reverse buckling rupture disks in high pressure applications, C-scored reverse buckling rupture disk assemblies including means for catching and supporting the hinge areas of the disks have been developed and used heretofore. For example, U.S. Pat. No. 4,759,460 issued Jul. 26, 1988 describes a C-scored reverse buckling rupture disk assembly which includes an arcuate inwardly extending projection on the downstream side of the rupture disk. The projection is positioned whereby upon rupture, the blow-out portion defined by the C-score wraps about the projection and the hinge connecting the blow-out portion to the rupture disk is supported. In order to insure that the reversal of the rupture disk starts adjacent the projection, a dent is included in the rupture disk or a portion of the rupture disk support member adjacent the hinge includes a relieved area therein.
While the use of the projection of U.S. Pat. No. 4,759,460 and other similar supporting means in scored reverse buckling rupture disk assemblies have reduced the incidents of fragmentation in high pressure applications, fragmentation has still occurred as a result of the blow-out portions of such rupture disks tearing at the hinge areas whereby they are disconnected from the rupture disks.
By the present invention an improved scored reverse buckling rupture disk assembly is provided wherein fragmentation of the rupture disk upon the reversal and rupture thereof is substantially eliminated, and even if the rupture disk is damaged it will still rupture below its design rupture pressure.